graph LR
A["RNNs<br/>(1980s)"] --> B["LSTMs<br/>(1997)"]
B --> C["Attention<br/>(2014)"]
C --> D["Transformers<br/>(2017)"]
D --> E["GPT / BERT<br/>(2018+)"]
style A fill:#9B8EC0,stroke:#1C355E,color:#fff
style B fill:#9B8EC0,stroke:#1C355E,color:#fff
style C fill:#00C9A7,stroke:#1C355E,color:#fff
style D fill:#FF7A5C,stroke:#1C355E,color:#fff
style E fill:#1C355E,stroke:#1C355E,color:#fff